// 封装倒计时逻辑函数
import {computed, onUnmounted, ref} from 'vue'
import dayjs from 'dayjs'
export function useCountDown() {
    // 1. 响应式数据
    const time = ref(0)
    let timer = null
    // 格式化时间
   const formatTime = computed(() => dayjs.unix(time.value).format('mm分ss秒'))
    // 2. 开启倒计时的函数
    function start(currentTime) {
        // 核心逻辑：每隔一秒就减一
        time.value = currentTime
       timer = setInterval(() => {
            time.value--
        }, 1000)

    }
    // 组件销毁时，清除定时器
    onUnmounted(() => {
       timer && clearInterval(timer)
    })

    return {
        formatTime,
        start
    }
}